Flow Modelling in Round Bloom Strands with electromagnetical stirring

For the majority of continuously cast semis for stringent applications such as wire rods, rails, seemless tubes, etc. an optimal cleanness, surface and sub-surface quality as well as a minimum of centre line segregation and central shrinkage porosity is almost mandatory. In-mould electromagnetic stirring (M-EMS) has a number of functions, but the primary purposes are to help breaking down coarse columnar dendritic solidification structure to produce a finer dendritic structure and a larger proportion of equiaxed structure. The rotary effect of M-EMS has also an important impact on the cleanness of the steels that can be explained by its action on exogenous and endogenous inclusions. The modelling of turbulent flow, steel temperature, solidification, exogenous inclusion transport and electromagnetical stirring with mathematical and – as far as possible – physical models are presented, including PIV-measurements on a 1:1 scale water-model of the strand.